Asthma is the most common chronic disease of children. In 1997 the National Asthma Education Program consensus panel, organized by NHLBI, revised the guidelines for the care and management of children and adults with asthma. The impact of these guidelines on asthma care in the US is unclear since hospitalization rates and mortality continue to rise. We hypothesize that the use of clinical practice guidelines will enhance the quality of asthma care and be a more cost-effective approach to the management of childhood asthma. We propose to evaluate the efficacy of a program designed to adhere to the NHLBI guidelines on asthma management in an emergency department (ED)/ observation unit (OU) setting. The study will utilize a prospective cohort design of all children 1-18 years seend in the emergency department at Connecticut Children's Medical Center for an asthma exacerbation. Data collection began in July 1998 and to date approximately 170 patients have been enrolled. A preliminary analysis revealed 126 patients with a 93% successful two week telephone follow-up rate. An abstract was submitted to the Ambulatory Pediatric Association Spring Meeting on the initial data and is entitled "Barriers to Compliance of a Clinical Practice Guideline (CPG) for Acute Childhood Asthma in a Pediatric Emergency Department". The sample size for this project has been revised. The total projected enrollment is 450, assuming an equal distribution of patients from the inpatient unit, observation unit and those discharged to home, are recruited.